S185 Developer Diversion of Southern Water Assets (Sewerage)

325050 A-DEVSRV-S185

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Diversion of public sewers S185 - Water Industry Act 1991
Section 185 of The Water Industry Act 1991 places a duty on a statutory undertaker such as Southern Water to alter or relocate any of its apparatus upon receipt of a notice to do so from any person with an interest in land upon which, under which or adjacent to which the public apparatus is installed, providing that the alteration or relocation of the apparatus is necessary to enable that person to carry out a proposed improvement of the land in which he has an interest and that it is reasonable to do so. No such duty arises where the apparatus is located in, under or over any street.

Where the undertaker carries out any work under section 185 by virtue of a notice having been served, the undertaker shall be entitled to recover any expenses reasonably incurred in carrying out those works from the person who served the notice.

You should read the following carefully prior to serving notice on Southern Water to relocate any of its apparatus.You must ensure that any project managers, consultants or contractors acting upon your behalf are aware of the costs, requirements and timings associated with diversionary works and that sufficient time has been allowed for the completion of the diversion prior to your starting to build on site.

Building over public sewers on new development or redevelopment sites is not permitted.

1. Who will carry out the work?
Southern Water will design and supervise the diversion and employ the contractor to carry out the works when:
  • The route of the diverted sewer passes through third party land, and/or
  • The sewer to be diverted is a critical sewer (this includes all rising mains) or there are specific operational requirements
  • The sewer to be diverted is a bonded asbestos cement pipe. This includes pipes described as asbestos cement (AC) and fibre reinforced cement (FRC)

However, Southern Water may permit the developer to carry out the work providing that:

  • The apparatus to be diverted is categorised as non-critical, and
  • The route of the diversion remains entirely within the boundary of the developers’ land.
The legal and financial arrangements will differ depending upon whether it is Southern Water or the developer who is carrying out the works.

2. Legal and financial arrangements
When a developer carries out the works
(Developer diversion S185)
The diversion will again need to be supported by an agreement. Fees will be invoiced directly to the developer or his agent and are not included in the fees or percentages detailed below. However, in this case there will be a slightly amended standard agreement to take into account the different financial arrangements.

In this case a refundable cash sum equal to the estimated cost of construction will have to be deposited with Southern Water.
3. What will it cost?
For all applications an initial fee, as per the application form, will be required.
Developer diversion
Where the route of the diversion will remain entirely within the development site boundary and the sewer is classified as non-critical, Southern Water will allow your consultants to design the diversion and for your contractor to carry out the works. The design should be carried out as per the specification contained in the current issue of Sewers for Adoption – a design and construction guide for developers.

The vetting and administration fee will be estimated on a time-related basis (minimum of eight hours) less the initial application fee.

The supervision fee will be 2.5% of the construction cost. Both the vetting and administration and the supervision fees will be payable prior to any instructions being given to our legal department for the preparation of the agreement.

We will require a cash sum as a surety equal to the estimated construction cost of the works which will be payable prior to, or at the same time that the diversion agreement is signed.

Your contractor will carry out the works at no cost to Southern Water and we will refund 80% of the cash sum once the works have been substantially completed to our satisfaction.
The remaining 20% plus any accrued interest will be refunded 12 months following the substantial completion and making good of any defects.

It should be noted that no works on the public sewerage system will be permitted until the Deed of Grant of Easement is in place, agreement signed, fees paid and surety lodged.
4. Additional requirements
Prior to you commencing any work on site, you must identify the positions and operational status of all laterals connecting to the section of sewer which is to be abandoned.

Should laterals be found you must obtain the written consent and authority of the owner of the lateral to reconnect their property to the new sewer.

You must ensure that the premises served by the lateral continue to be drained with at least equal effectiveness once the works have taken place.

These approvals should be included in your initial submission.

We will also require a method statement detailing how you are intending to deal with existing flows during the course of the works.

Please note: It is not permissible to discharge foul sewerage into road gullies, surface water sewers, ditches, the trench or watercourses. Nor should ground water be discharged into any public sewer or surface water discharged into the foul water system without the express permission of Southern Water.

Buildings should be located at least three metres away from the diverted sewer where the depth from ground level to invert level is less than three metres. In circumstances of greater depth, large diameter sewers, unusual ground profile or material a greater distance may be required.

On completion of the works the redundant section(s) of the existing public sewers will be made safe by removing them from the ground.

Three full sets of as constructed drawings showing the diversion works and the health and safety file, as may be required by the Construction (Design and Management) Regulations 2015 will also be required.

5. How long will it take?
Developer diversion

You should provide all the information detailed in these guidance notes, as it is upon this that the estimate will be based. Any subsequent requests for additional or alternative routes or revised estimates will be subject to further charges.

Upon receipt of this information we will consider the options and inform you within 28 days if your proposals are acceptable. At the same time we will provide you with our estimate of the cost of the works (if different from your own) and the fees that will be required.

You should be aware that any deviation from the standard form of agreement may affect the works programme and anticipated costs.

Please note: All legal fees will be separately invoiced by Southern Water’s solicitor and must be paid before the agreement is engrossed.

All pipework 300mm nominal bore and smaller must be certified by a recognised third party test body as proven capable of being jetted using pressures of 2700 psi. All ancillary equipment made of plastic materials such as chambers and elements in association with such pipework must be similarly proven capable of being jetted using pressures of 2700 psi.

Pipework of greater than 300mm nominal bore must be certified by a recognised third party test body as proven capable of being jetted using pressures of 2600 psi. All ancillary equipment made of plastic materials such as chambers and elements in association with such pipework must be similarly proven capable of being jetted using pressures of 2600 psi.

For a typical diversion agreement please contact:

Legal and Property Services
Southern Water
Southern House
Yeoman Road
West Sussex
BN13 3NX
Please check your site is in the Southern Water catchment area: https://www.southernwater.co.uk/your-area

Contact details:

Number of Properties:

Domestic: *
Non-domestic: *
  • Copies of the drainage layout plan at 1:100 (or larger), showing location of sewers and manholes on site and up to the connection point
  • Third party land owner information (if applicable)
  • Copy of planning consent
  • A site plan: Development site edged in green (1:2500)
  • Site location plan at 1:1250 (or larger)

  • Site boundary clearly shown
  • Roads clearly shown
  • Adjacent buildings clearly shown
  • Private pipe run to Southern Water network clearly shown
  • Maximum file limit is 50MB
  • Allowed file types are DOCX, DOC, PDF, XLS, XLSX, JPG, JPEG, BMP, PNG, DWG (auto cad), DXF (auto cad), DGN (microstation), PRP (microstation), PRW (microstation)
  • Due to current Southern Water policies, we can only review drawings submitted in paper format in the intended scale/paper size and colour.
    We accept your drawings/plans by uploading them to the portal alternatively you can post these to our Developer Services team.
Warning! File size too big. Maximum file size 50MB.
Failure to include any of the requested information will be deemed as an incomplete application and may result in this application being delayed/returned. This application DOES NOT mean approval has been granted. No work should commence until written approval has been given by Southern Water.
The contents of the report are for direct use only by the applicant and are to be kept private and confidential. They may only be disclosed to third parties with the written approval of Southern Water. Such third parties to have no subsequent implied or other right to disclose the contents and information to any other parties.
Amount to pay
Diversion of Sewer
VAT (20%)
Total Fee
Do you require a VAT receipt? *
Preferred payment method:
Application number:
Amount to pay: £

Payments can be made directly via BACS transfer to:

Southern Water Services Ltd
Miscellaneous Income Account
HSBC Bank Plc
P O Box 125, 2nd Floor, 62-76 Park Street,
SE1 9DZ, London, England

Sort Code - 40-02-50
Account No - 81426834

(However please ensure that you confirm the application number you are making payment for in the reference line)

Please make cheques payable to Southern Water Services Ltd.
Your printed slip and cheque should then be sent to:

Miscellaneous Income
Southern Water
PO Box 4056
BN13 3XX

Please click on ‘Print Preview’ and confirm your cheque number is on the preview slip.
Please print the slip and attach the cheque after writing the application number on the back in case they are separated.

Please provide the following where applicable and tick the box if enclosed:

A site plan: Development site edged in green (1:2500)
Third party land owner information (if applicable)
Site location plan at 1:1250 (or larger)
Copies of the drainage layout plan at 1:100 (or larger), showing location of sewers and manholes on site and up to the connection point
Copy of planning consent

Please note:

  • Failure to complete this application in full and provide relevant information will result in the application being delayed or returned.
  • This application DOES NOT mean approval has been granted.
  • No work should commence until written approval has been given by Southern Water.
  • We do not accept any drawings unless they have been provided in full size and in paper format.

I/we hereby request diversion of Southern Water asset(s) under Section 185 of the Water Industry Act 1991 at the new development site detailed above and edged green on the attached 1:2500 Ordnance Survey extract.

I/we undertake to pay Southern Water reasonable costs incurred in implementing the diversion scheme. Please note, by signing this application you are not automatically granted technical approval or guaranteed adoption